A pyroelectric polymer composite material and a preparation method thereof

Abstract

The present invention relates to the technical field of functional materials, and particularly relates to a pyroelectric polymer composite material and a preparation method thereof. The composite material is composed of PVDF and modified BaTiO3, wherein the modified BaTiO3 is selected from one or more of copper phthalocyanine sebacate modified BaTiO3@SiO2, copper phthalocyanine stearate modified BaTiO3@SiO2, copper phthalocyanine octadecanedioate modified BaTiO3@SiO2, and copper phthalocyanine dopamine modified BaTiO3@SiO2. In the present invention, the composite material of PVDF and BaTiO3 modified with different organic acids and (tetraaminophthalocyanine) copper can effectively combine the advantages of both, utilize the high pyroelectric coefficient of BaTiO3 and the flexibility of PVDF to improve the performance of the composite material in pyroelectric applications. The preparation method of the composite material is simple, low-cost, and pollution-free, and is suitable for large-scale industrial production. In addition, the materials used are all environmentally friendly and meet the requirements of sustainable development.

Description

Technical Field

[0001] The present invention relates to the technical field of functional materials, and particularly to a pyroelectric polymer composite material and a preparation method thereof. Background Art

[0002] Pyroelectric materials are a branch of piezoelectric materials and have been widely used in many fields such as infrared detectors and fire alarms. At present, pyroelectric materials mainly include crystal materials, ceramic materials, polymer materials, and ceramic-polymer composite materials. Among these materials, crystal materials are widely used because of their high pyroelectric coefficient, low dielectric constant, and high detection sensitivity, but their cost is relatively high. The cost of ceramic materials is lower than that of crystal materials, but there are certain difficulties in processing. In contrast, polymer materials have good flexibility, low cost, and are easy to be made into large-area uniform thin films. Among them, polyvinylidene fluoride (PVDF) is the most commonly used polymer pyroelectric material. PVDF is a crystalline polymer, and its crystal forms include α, β, γ, etc. Only the β crystal has pyroelectric properties. When PVDF is melted and then cooled and crystallized, it mainly forms α crystals, which do not have pyroelectric properties at this time. However, when the α crystal is stretched at a temperature below its melting point, it will transform into the β crystal, thereby obtaining pyroelectric properties.

[0003] Taking barium titanate (BT) material as an example, although it belongs to the ABO3 perovskite structure, its crystal structure does not have a center of symmetry. Under normal pressure, BT exhibits a structure that seemingly belongs to the cubic crystal system, but its actual structure is actually the tetragonal crystal system. As a common pyroelectric material, the pyroelectric coefficient of BT performs moderately well and can meet some application scenarios with low requirements for pyroelectric performance. However, the Curie temperature of BT is only 120 °C, which limits its use only at room temperature. When the temperature exceeds 100 degrees Celsius, the performance of BT will significantly decline and it will no longer be applicable. In addition, the dielectric loss and temperature coefficient of BT are relatively high, which also limits its application scope to a certain extent. Summary of the Invention

[0004] To solve the problems existing in the prior art, the present invention provides a pyroelectric polymer composite material and a preparation method thereof.

[0005] A pyroelectric polymer composite material, the composite material is composed of PVDF and modified BaTiO3, wherein the modified BaTiO3 is selected from one or more of copper phthalocyanine sebacate modified BaTiO3@SiO2, copper phthalocyanine stearate modified BaTiO3@SiO2, copper phthalocyanine octadecanedioate modified BaTiO3@SiO2, and copper phthalocyanine dopamine modified BaTiO3@SiO2.

[0006] Further, the modified BaTiO3 is selected from copper phthalocyanine sebacate modified BaTiO3@SiO2.

[0007] Further, the mass ratio of the copper phthalocyanine sebacate modified BaTiO3@SiO2 to PVDF is 1-10:100.

[0008] Further, the mass ratio of the copper phthalocyanine sebacate modified BaTiO3@SiO2 to PVDF is 5:100.

[0009] Further, the preparation method of the copper phthalocyanine sebacate modified BaTiO3@SiO2 is as follows: Take 1 g of BaTiO3@SiO2 and disperse it in 200 mL of 10 mM Tris-HCl buffer solution with a pH of about 8.5, and ultrasonicate for 30 min; then add 500 mg of sebacic acid, heat the mixed solution to 60 °C, stir at 60 °C for 24 h, then add 300 mg of copper (tetraaminophthalocyanine), stir at 60 °C for 12 h, centrifuge to obtain a precipitate, and finally wash it twice with water and absolute ethanol respectively, and dry it overnight in a vacuum freeze dryer to obtain copper phthalocyanine sebacate modified BaTiO3@SiO 2。

[0010] Further, the preparation method of the BaTiO3@SiO2 is as follows: Add 1 g of BaTiO3 powder to 200 mL of ethanol, and ultrasonically disperse for 1 h; then add 10 mL of deionized water and 12 mL of ammonia water; after stirring for 15 min, at room temperature of 30 °C, add 2 mL of TEOS dropwise while stirring, and continue to stir at room temperature of 30 °C for 2 h after the addition; obtain a precipitate by centrifugation, wash the precipitate twice with water and absolute ethanol respectively, and dry it overnight in a vacuum freeze dryer to obtain BaTiO3@SiO2.

[0011] The present invention also provides a preparation method of a pyroelectric polymer composite material, comprising the following steps:

[0012] Step S1: Take PVDF powder and add it to DMF, and stir at 75 °C for 2 h;

[0013] Step S2: Weigh the modified BaTiO3@SiO2 and add it to DMF, and ultrasonicate for 20 min; the modified BaTiO3 is selected from one or more of copper phthalocyanine sebacate modified BaTiO3@SiO2, copper phthalocyanine stearate modified BaTiO3@SiO2, copper phthalocyanine octadecanedioate modified BaTiO3@SiO2, and copper phthalocyanine dopamine modified BaTiO3@SiO2;

[0014] Step S3: Slowly add the solution obtained in Step S2 to the solution in Step S1, stir while adding, and then heat and stir the resulting mixed solution for 3 h;

[0015] Step S4: Pour the mixed solution obtained in Step S3 onto a casting substrate and dry it in a vacuum drying oven at 65 °C for 12 h;

[0016] Step S5: Sputter aluminum electrodes on both sides of the obtained thin film.

[0017] Further, in Step S3, heat the resulting mixed solution to 60 - 85 °C.

[0018] Further, in Step S3, heat the resulting mixed solution to 70 - 80 °C.

[0019] Further, in Step S3, heat the resulting mixed solution to 75 °C.

[0020] The present invention is achieved through the following technical solutions:

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects: The composite material of PVDF and copper-modified BaTiO3 with different organic acids and (tetraaminophthalocyanine) can effectively combine the advantages of both. Utilize the high pyroelectric coefficient of BaTiO3 and the flexibility of PVDF to improve the performance of the composite material in pyroelectric applications. The preparation method of this composite material is simple, low-cost, and pollution-free, suitable for large-scale industrial production. In addition, the materials used are all environmentally friendly and meet the requirements of sustainable development. Specific Embodiments

[0022] To make the purpose, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0023] In the present invention, PVDF is polyvinylidene fluoride and is of the β crystal form; the CAS of sebacic acid is: 111 - 20 - 6; DMF is N,N-dimethylformamide; the CAS number of octadecanedioic acid is 871 - 70 - 5; the CAS number of copper (tetraaminophthalocyanine) is 28632 - 30 - 6.

[0024] Example 1

[0025] A pyroelectric polymer composite material is composed of PVDF and copper phthalocyanine modified BaTiO3@SiO2 with sebacic acid.

[0026] Its preparation method is as follows:

[0027] Step S1: Add 2.5 g of PVDF powder into 12 g of DMF, and stir for 2 h at 75 °C;

[0028] Step S2: Weigh 0.125 g of copper phthalocyanine sebacate modified BaTiO3@SiO2, add it into 12 g of DMF, and ultrasonicate for 20 min;

[0029] Step S3: Slowly add the solution obtained in Step S2 into the solution of Step S1 while stirring, then heat the resulting mixed solution to 75 °C and stir for 3 h;

[0030] Step S4: Pour the mixed solution obtained in Step S3 onto a casting substrate, and dry it in a vacuum drying oven at 65 °C for 12 h;

[0031] Step S5: Sputter aluminum electrodes on both sides of the obtained thin film.

[0032] The preparation method of the copper phthalocyanine sebacate modified BaTiO3@SiO2 is as follows:

[0033] Add 1 g of BaTiO3 powder into 200 mL of ethanol, and ultrasonically disperse for 1 h; then add 10 mL of deionized water and 12 mL of ammonia water; after stirring for 15 min, while stirring, gradually add 2 mL of TEOS dropwise at room temperature of 30 °C. After the addition is completed, continue to stir at room temperature of 30 °C for 2 h; obtain a precipitate by centrifugation, wash the precipitate twice with water and absolute ethanol respectively, and dry it overnight in a vacuum freeze-drying oven to obtain BaTiO3@SiO2;

[0034] Take 1 g of BaTiO3@SiO2 and disperse it in 200 mL of 10 mM Tris-HCl buffer solution with a pH of about 8.5, and ultrasonicate for 30 min; then add 500 mg of sebacic acid, heat the mixed solution to 60 °C, stir at 60 °C for 24 h, then add 300 mg of (tetraaminophthalocyanine) copper, stir at 60 °C for 12 h, obtain a precipitate by centrifugation, and finally wash it twice with water and absolute ethanol respectively, and dry it overnight in a vacuum freeze-drying oven to obtain copper phthalocyanine sebacate modified BaTiO3@SiO2.

[0035] Example 2

[0036] A pyroelectric polymer composite material is composed of PVDF and copper phthalocyanine stearate modified BaTiO3@SiO2.

[0037] Its preparation method is as follows:

[0038] Step S1: Add 2.5 g of PVDF powder into 12 g of DMF, and stir for 2 h at 75 °C;

[0039] Step S2: Weigh 0.125 g of copper phthalocyanine stearate modified BaTiO3@SiO2, add it to 12 g of DMF, and ultrasonicate for 20 min;

[0040] Step S3: Slowly add the solution obtained in Step S2 to the solution in Step S1 while stirring, and then heat the resulting mixed solution to 75 °C and stir for 3 h;

[0041] Step S4: Pour the mixed solution obtained in Step S3 onto a casting substrate and dry it in a vacuum drying oven at 65 °C for 12 h;

[0042] Step S5: Sputter aluminum electrodes on both sides of the obtained thin film.

[0043] The preparation method of the copper phthalocyanine stearate modified BaTiO3@SiO2 is as follows:

[0044] Add 1 g of BaTiO3 powder to 200 mL of ethanol, and ultrasonically disperse for 1 h; then add 10 mL of deionized water and 12 mL of ammonia water; after stirring for 15 min, at room temperature of 30 °C, add 2 mL of TEOS dropwise while stirring, and after the addition is completed, continue to stir at room temperature of 30 °C for 2 h; obtain a precipitate by centrifugation, wash the precipitate twice with water and absolute ethanol respectively, and dry it overnight in a vacuum freeze-drying oven to obtain BaTiO3@SiO2;

[0045] Take 1 g of BaTiO3@SiO2 and disperse it in 200 mL of 10 mM Tris-HCl buffer solution with a pH of about 8.5, and ultrasonicate for 30 min; then add 500 mg of stearic acid, heat the mixed solution to 60 °C, stir at 60 °C for 24 h, then add 300 mg of (tetraaminophthalocyanine) copper, stir at 60 °C for 12 h, obtain a precipitate by centrifugation, and finally wash it twice with water and absolute ethanol respectively, and dry it overnight in a vacuum freeze-drying oven to obtain copper phthalocyanine stearate modified BaTiO3@SiO2.

[0046] Example 3

[0047] A pyroelectric polymer composite material is composed of PVDF and copper phthalocyanine octadecanedioate modified BaTiO3@SiO2.

[0048] Its preparation method is as follows:

[0049] Step S1: Take 2.5 g of PVDF powder and add it to 12 g of DMF, and stir at 75 °C for 2 h;

[0050] Step S2: Weigh 0.125 g of copper phthalocyanine octadecanedioate modified BaTiO3@SiO2, add it to 12 g of DMF, and ultrasonicate for 20 min;

[0051] Step S3: Slowly add the solution obtained in Step S2 to the solution in Step S1 while stirring, and then heat the resulting mixed solution to 75 °C and stir for 3 h;

[0052] Step S4: Pour the mixed solution obtained in Step S3 onto a casting substrate and dry it in a vacuum drying oven at 65 °C for 12 h;

[0053] Step S5: Sputter aluminum electrodes on both sides of the obtained thin film.

[0054] The preparation method of the copper phthalocyanine octadecanedioate modified BaTiO3@SiO2 is as follows:

[0055] Add 1 g of BaTiO3 powder to 200 mL of ethanol, and ultrasonically disperse for 1 h; then add 10 mL of deionized water and 12 mL of ammonia water; after stirring for 15 min, at room temperature of 30 °C, add 2 mL of TEOS dropwise while stirring, and continue to stir at room temperature of 30 °C for 2 h after the addition; obtain a precipitate by centrifugation, wash the precipitate twice with water and absolute ethanol respectively, and dry it overnight in a vacuum freeze-drying oven to obtain BaTiO3@SiO2;

[0056] Take 1 g of BaTiO3@SiO2 and disperse it in 200 mL of 10 mM Tris-HCl buffer solution with a pH of about 8.5, and ultrasonicate for 30 min; then add 500 mg of octadecanedioic acid, heat the mixed solution to 60 °C, stir at 60 °C for 24 h, then add 300 mg of copper (tetraaminophthalocyanine), stir at 60 °C for 12 h, centrifuge to obtain a precipitate, and finally wash it twice with water and absolute ethanol respectively, and dry it overnight in a vacuum freeze-drying oven to obtain copper phthalocyanine octadecanedioate modified BaTiO3@SiO2.

[0057] Example 4

[0058] A pyroelectric polymer composite material is composed of PVDF and copper phthalocyanine dopamine modified BaTiO3@SiO2.

[0059] Its preparation method is as follows:

[0060] Step S1: Take 2.5 g of PVDF powder and add it to 12 g of DMF, and stir at 75 °C for 2 h;

[0061] Step S2: Weigh 0.125 g of copper phthalocyanine dopamine modified BaTiO3@SiO2, add it to 12 g of DMF, and ultrasonicate for 20 min;

[0062] Step S3: Slowly add the solution obtained in Step S2 to the solution in Step S1 while stirring, and then heat the resulting mixed solution to 75°C and stir for 3 h;

[0063] Step S4: Pour the mixed solution obtained in Step S3 onto a casting substrate and dry it in a vacuum drying oven at 65°C for 12 h;

[0064] Step S5: Sputter aluminum electrodes on both sides of the obtained thin film.

[0065] The preparation method of the copper phthalocyanine dopamine-modified BaTiO3@SiO2 is as follows:

[0066] Add 1 g of BaTiO3 powder to 200 mL of ethanol and ultrasonically disperse for 1 h; then add 10 mL of deionized water and 12 mL of ammonia water; after stirring for 15 min, at room temperature of 30 °C, add 2 mL of TEOS dropwise while stirring, and after the addition is completed, continue to stir at room temperature of 30 °C for 2 h; obtain a precipitate by centrifugation, wash the precipitate twice with water and absolute ethanol respectively, and dry it overnight in a vacuum freeze-drying oven to obtain BaTiO3@SiO2;

[0067] Take 1 g of BaTiO3@SiO2 and disperse it in 200 mL of 10 mM Tris-HCl buffer solution with a pH of about 8.5, and ultrasonically treat for 30 min; then add 500 mg of dopamine, heat the mixed solution to 60 °C, stir at 60 °C for 24 h, then add 300 mg of copper (tetraaminophthalocyanine), stir at 60 °C for 12 h, obtain a precipitate by centrifugation, and finally wash it twice with water and absolute ethanol respectively, and dry it overnight in a vacuum freeze-drying oven to obtain copper phthalocyanine dopamine-modified BaTiO3@SiO2.

[0068] The pyroelectric coefficient is tested according to the method specified in GB / T 11297.8 2015, and the pyroelectric coefficient at 25 °C is calculated.

[0069]

[0070] The specific embodiments described above have further elaborated on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pyroelectric polymer composite, characterized in that, The composite material is composed of PVDF and modified BaTiO3, wherein the modified BaTiO3 is selected from one or more of copper phthalocyanine sebacate modified BaTiO3@SiO2, copper phthalocyanine stearate modified BaTiO3@SiO2, copper phthalocyanine octadecanedioate modified BaTiO3@SiO2, and copper phthalocyanine dopamine modified BaTiO3@SiO2; The preparation method of the modified BaTiO3 is as follows: Take 1 g of BaTiO3@SiO2 and disperse it in 200 mL of 10 mM Tris-HCl buffer solution with a pH of 8.5, and ultrasonically treat for 30 min; then add 500 mg of one of sebacic acid, stearic acid, octadecanedioic acid, and dopamine, heat the mixed solution to 60 °C, stir at 60 °C for 24 h, then add 300 mg of (tetraaminophthalocyanine) copper, stir at 60 °C for 12 h, centrifuge to obtain a precipitate, and finally wash it twice with water and anhydrous ethanol respectively, and dry it overnight in a vacuum freeze-drying oven to obtain modified BaTiO3@SiO2.

2. The pyroelectric polymer composite according to claim 1, wherein The modified BaTiO3 is selected from copper phthalocyanine sebacate modified BaTiO3@SiO2.

3. The pyroelectric polymer composite according to claim 2, characterized in that, The mass ratio of the copper phthalocyanine sebacate modified BaTiO3@SiO2 to PVDF is 1-10:

100.

4. The pyroelectric polymer composite according to claim 3, wherein The mass ratio of the copper phthalocyanine sebacate modified BaTiO3@SiO2 to PVDF is 5:

100.

5. The pyroelectric polymer composite according to claim 1, characterized in that, The preparation method of the BaTiO3@SiO2 is as follows: Add 1 g of BaTiO3 powder to 200 mL of ethanol, and ultrasonically disperse for 1 h; then add 10 mL of deionized water and 12 mL of ammonia water; after stirring for 15 min, at room temperature of 30 °C, add 2 mL of TEOS dropwise while stirring, and after the addition is completed, continue to stir at room temperature of 30 °C for 2 h; obtain a precipitate by centrifugation, wash the precipitate twice with water and anhydrous ethanol respectively, and dry it overnight in a vacuum freeze-drying oven to obtain BaTiO3@SiO2.

6. The preparation method of the pyroelectric polymer composite material according to any one of claims 1 to 5, characterized in that, It includes the following steps: Step S1: Take PVDF powder and add it to DMF, and stir at 75 °C for 2 h; Step S2: Weigh the modified BaTiO3 and add it to DMF, and ultrasonically treat for 20 min; the modified BaTiO3 is selected from one or more of copper phthalocyanine sebacate modified BaTiO3@SiO2, copper phthalocyanine stearate modified BaTiO3@SiO2, copper phthalocyanine octadecanedioate modified BaTiO3@SiO2, and copper phthalocyanine dopamine modified BaTiO3@SiO2; Step S3: Slowly add the solution obtained in Step S2 to the solution in Step S1, stir while adding, and then heat and stir the obtained mixed solution for 3 h; Step S4: Pour the mixed solution obtained in Step S3 onto a casting substrate and dry it in a vacuum drying oven at 65 °C for 12 h; Step S5: Sputter aluminum electrodes on both sides of the obtained film.

7. The preparation method of the pyroelectric polymer composite material according to claim 6, characterized in that In Step S3, heat the obtained mixed solution to 60-85 °C.

8. The preparation method of the pyroelectric polymer composite material according to claim 7, characterized in that, In Step S3, heat the obtained mixed solution to 70-80 °C.

9. The preparation method of the pyroelectric polymer composite material according to claim 8, characterized in that, In the step S3, heat the obtained mixed solution to 75 °C.

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